[PATCH 17/17] idr: Warn if old iterators see large IDs
From: Matthew Wilcox <willy@infradead.org>
Date: 2017-11-28 21:38:28
Also in:
lkml
Subsystem:
library code, the rest, xarray · Maintainers:
Andrew Morton, Linus Torvalds, Matthew Wilcox
From: Matthew Wilcox <redacted> Now that the IDR can be used to store large IDs, it is possible somebody might only partially convert their old code and use the iterators which can only handle IDs up to INT_MAX. It's probably unwise to show them a truncated ID, so settle for spewing warnings to dmesg, and terminating the iteration. Signed-off-by: Matthew Wilcox <redacted> --- lib/idr.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/lib/idr.c b/lib/idr.c
index 772a24513d1e..f56133a600bb 100644
--- a/lib/idr.c
+++ b/lib/idr.c@@ -145,7 +145,11 @@ int idr_for_each(const struct idr *idr, void __rcu **slot; radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, 0) { - int ret = fn(iter.index, rcu_dereference_raw(*slot), data); + int ret; + + if (WARN_ON(iter.index > INT_MAX)) + break; + ret = fn(iter.index, rcu_dereference_raw(*slot), data); if (ret) return ret; }
@@ -173,6 +177,9 @@ void *idr_get_next(struct idr *idr, int *nextid) if (!slot) return NULL; + if (WARN_ON_ONCE(iter.index > INT_MAX)) + return NULL; + *nextid = iter.index; return rcu_dereference_raw(*slot); }
--
2.15.0